Fire resistant-extreme pressure and hydrolysis resistant lubricant comprising polychlorinated diphenyl and triaryl phosphates



BEST AVAILABLE COPY 14, 1967 (3.0. GROSLAMB ERT 3,352,780

FIRE RESISTANT- EXTREME PRESSURE AND HYDROLYSIS RESISTANT LUBRICANT COMPRISING POLYCHLORINATED DIPHENYL v AND TRIARYL PHOSPHATES Filed June 23; 1965 3 I i I 1 g i I i l 1 9.

l l l 1 g l l g l w l 5 Lu 1 h i :1 3 a: A Q. a. a, z &m 2 :5 7 "TIT/ a i 5 a a v l N N E 0) RV, I o 5 2% a: w l E i a s g SONfiOd-OVO1 nq E R GEORGES GASTON GROSLAMBERT WVEW Q United States Patent FIRE RESISTANT-EXTREME PRESSURE AND HY- DROLYSIS RESISTANT LUBRICANT COMPRIS- ING POLYCHLORINATED DIIIIENYL AND TRI- ARYL PIIOSPHATES Georges Gaston Groslambert, Etterbeek, Belgium, assignor to Laholina, Soc. Am, Brussels, Belgium, :1 corporation of Belglum Filed June 23, 1965, Ser. No. 466,192 6 Claims. (Cl. 252-333) This invention relates to a non-flammable lubricant having improved extreme pressure and non-sludging characteristics. While it has many lubricant applications, itsis particularly useful as a lubricant for turbines as well as reduction gearing for turbines, lubrication of gas compressons, and other extreme pressure, and non-flammable, fireresistant uses. Other useful applications are as hydraulic fiuid and heat transfer fluid.

The lubricant hereof comprises a poly-chlorinated diphcnyl as the main component, containing from about 0.5 to preferably about 2 to.4%, of a phosphoric ester. The composition further usually includes additives for imparting improved non-foaming, viscosity index improving, anti-rust and anti-oxidant characteristics.

In general aspect this invention is to specific improvement over such non-flammable oils commonly used in the art, comprising polychlorinated diphenyl and triaryl phosphates usually blended in proportions of /80 to 80/20. While such lubricants are used for their fire-resistant properties as turbine oils, they are corrosive and sludge-forming when subject to the standard ASTM.D.943 Turbine Oil oxidation stability tests, properties which are cured in the present invention.

Accordingly to the present invention, it is found that the reduction of the phosphoric ester to the critical range of the 0.5 to 5% of the mixture with poly-chlorinated diphenyl, in the presence of usual oxidation or rust inhibitors, forms a far superior lubricant to the composition stated in respect to corrosion resistance and sludge formation, and indeed this lubricant readily passes the ASTMD. 943 minimum test standards for turbine oils.

Surprisingly, moreover, in the preferred narrower range of 2 to 4% of aryl phosphoric ester to poly-chlorinated diphenyl, the lubricant acquires markedly superior extreme pressure characteristics and, in fact, the curves shown in the drawing herewith reach a maximum peak at about a 3% phosphoric ester content in the lubricant. That 3% peak is shown to be variable in extreme pressure values only with the character of the phosphoric ester, but not essentially with the quantity thereof present in the lubricant. There is apparent synergistic cooperation between the phosphoric ester and the poly-chlorinated diphenyl component in the quantity stated. The surprisingly high extreme pressure results are obtained in the narrower 2 to 4% range stated; but improved resistance to increase in acidity and sludge formation during long oxidation, according to the said ASTM test, is in the larger quantity 0.5 to 5% range stated.

The poly-chlorinated diphenyl may be tri-chlorinated diphenyl, tetra-chlorinated diphenyl or penta-chlorinated diphenyl or mixtures thereof.

The phosphoric ester may be any liquid trihydrocarbyl ester of ortho phosphoric acid of the formula wherein R is monocarbocyclic aryl such as phenyl, tolyl, xylenyl, cumenyl, ethyl phenyl, as well as mixed types wherein the hydrocarbon components of the ester as defined may be mixed. I prefer the phosphoric esters of monocarbocyclic aryl and aryls having lower alkyl substituents wherein the alkyl is methyl or ethyl. Typically,

BEST AVAILABLE COPY preferred phosphoric esters are triphenyl phosphate, tricresyl phosphate, trixylenyl phosphate, phenyl discrcsyl phosphate and diphenyl cresyl phosphate, and the like.

Other valuable properties are imparted to the lubricant by the optional addition of certain additives. Typical additives are foam inhibitors, rust inhibitors, anti-oxidants and viscosity index improvers. These are usually used in quantities from 0 to 3%, such as from 0.1 to 3% by weight, except that the viscosity index improver would be used in quantity up to 10%, such as from 2 to 10%.

Accordingly, the composition of this invention comprises 0.5 to 5% of phosphoric ester, optionally further containing an additive of the character stated, and the balance being polychlorinated diphenyl.

It is known in the art to use foam inhibitors such as polymethoxy silane or poly-phenoxy silane of a molecular weight in the range of about 2,000 to 10,000, such additives having a very short life tending to precipitate out of the oil upon the filter or to be absorbed by sludge and dusts entering the system. It is preferred to use alphachloro-naphthalene in the quantity range stated, preferably about 0.5 to 3%. This defoaming material greatly reduces the foaming tendency even over large temperature ranges and what foam forms under accelerated tests is quite unstable and will quickly break.

As anti-oxidant it is preferred to use higher alkyl phenols, typically ditertiary butyl phenol or ditertiary butyl cresol, usually used in quantity from about 0.05 to 3%, preferably about 0.5 to 1%.

As rust inhibitor, alkaline earth metal sulfonate, for instance calcium sulfonate, may be used. Altcrnately, 01 combined with said calcium sulfonate, a higher alkyl Ol alkenyl succinic acid, preferably having from 16 to 2( carbon atoms, typically octadecenyl-succinic acid, may be used as rust inhibitor. Such rust inhibitors are in quantity of up to 1% and are preferably used in quantity of 0.0]

'to 0.5% or more.

For improving the viscosity index, I prefer to use 2 lower alkyl such as 1' to 5 carbon atoms polymerized lowe: valkyl acrylic or methacrylic ester such as polymethy acrylate, polybutyl acrylate, polymethyl methacrylate o polybutyl methacrylate having from 5,000 to 15,00 molecular weight, a typical example of which is poly-buty acrylate of molecular weight of about 10,000. Such vis cosity index improver is usually added in quantity 0 about 2 to 10%, preferably about 4 to 6%.

To illustrate the synergistic effect upon the extrem pressure properties of a small quantity of a phosphat ester In a poly-chloro diphenyl lubricant, several tests wer performed in a Timken machine and the film strength we measured for a series of lubricant blends as describe above, all comprising triaryl phosphate esters mixed wit tetra-chloro diphenyl in the critical quantity range of l t 5% by weight, and the film strength was plotted to 0k tain a series of curves shown in the attached drawin These several phosphate esters tested were: (1) tricres phosphate, (2) diphenyl cresyl phosphate, (3) triphen phosphate, and (4) trixylenyl phosphate. The actual temethod is identified as Fed. method Std. 791a, No. 650. The tricresyl phosphate was superior, as the curves Sh0\ with diphenyl cresyl coming next.

Additional Timken machine tests upon blends with 0th poly-chlorinated diphenyls were conducted and the fil strength is recorded in Table I. The specific identity the compositions 2, 3, 4 and 5 are set forth under cor positions 2, 3, 4 and 5 of Table II below. These compo: tions were particularly included in this test to illustra that other additives present for other purposes such anti-oxidant, rust inhibitor, or viscosity index improvt have no significant effect upon the extreme pressure pro erties.

3 52 7 BEST AVAILABLE COPY 3 4 TABLE L-TIMKEN MACHINE TESTS (FED. METHOD STD TABLE L-Continued O.K. Rupture O.K. Rupture load, at the ifind n81 the 5 lbs. tiim, lbs.

15. n, lbs.

57% trichiorinnted diphonyi, 40% pentoehio- Composition No.: rinntod tiiphonyl, 3% tricrosylphospluito. 4G 60 2 30 33 50% trichlorinntod (liphenyi, 50% poutueiiio- 4t) 43 rinated diphenyl 30 33 40 r 5. 40 43 HWY .hlnrinnleddi hon 30 33 ll) lmfli totinchlorinutcd milit -1, 3O 3 It IS quite surprising that each of these rrctlaaelnals in th?1 HOS]! intn C 5 m Siren 1 08 tvtrnehlorlnntoti diphonyi, 2% tricrcsyi- ,cluanmy,range staufd shows much ma 6 g J t llospllllin 33 30 in the minor quantity range of ester 1n the blend. The ac 'itllllitffflfil.flfifiiififi f.ff.ff??'.j. to 50 m1 film strengths my somewhat, Phosphor? we 00 tcttlnehiorlnntod tlipltony], 4% tt'teresyi- 4 43 from the next, but all seem to show a peak of effectiveness tosp tutu 0 g mmcmmmmd dummy! 5% in concentration of about 3%, tapering off to a plateau hosphate 40 43 between about 2 and 4%, as illustrated 1n the C rves. For D0:ififiulfmflrlmtted (lipllenyl. to? ui y 40 43 this reason applicant prefers in this sub-group of trtaryi so tetr n, iorituttod diphonyi, tricresyim 43 phosphates to use a concentration in the range of 2 to {I lost) nun 0 0 Imp/o mmsvnmnsnhnm H 40 43 20 4b, the concentration of 3 i; being vastly superior as an i'ii(' i (i H L'( I) H! y 0 F X til) z t l ril i ii I n i 7 t l 30 33 unusual peak in each of the curves illustrat ng the extreme l ]h' h' h' hsl l i,;;.1[,;{ pressure CIICCI'IIIZIXIHIUIII at thts concentration.

y *i l" 30 33 The following eighteen examples set forth In tabular ;I,'J 3 40 form illustrate the effect of the low concentration, 0.5 to 06% lctruv 5% of the phosphate ester to resist corrosion and sludge thosphnlo t I. 33 i punctual-hum. dmhunyll 5% "WWW. I format1on, 1n some contrast to higher concentration in the g u -n poly-chlorinated diphenyl base when SlibjCCt to the standi' X) (iifv' I) I03 i iii t.. 0 IYJZ, lt'llilttliltwiiiillbll diphm 1% tiiphonyin ard ASTM.D.943 Turbine Oil OXltldtlOtt Stability test.

trl-sy piospmto l 4 it) u tlfil'}, tutrnchlortnutnti tiiphonyi, 2% dlphonyl- I 30 film oxldluon SllPlhly i j? of l -W t t 30 into a selected quantity of Oil containing polished corrodrm x, it'llilicliltiillliltlttll (llplilmyl, 3% tlipilttttyl- 43 46 bie metals in this case a coil of polished copper and steel,

L'i'th') I 108 iii 1 t w I 2? ig m gt mm v u' u u' 33 3c and measuring the acidity developed in the Oil, the coros im m etito rtnut'd'dipii'ni'if 's'z'kit'ptihlv't n m rosion of the metal, and the quantity of sludge developedCi crcsy [HOSP into t e a 100% (1t henylcrosylphosplmte 33 30 Table II sets forth the actual compositions test d, n 7 wtritwlllm'irmw p n y 30 33 Table III sets forth the results of the tests. Certain of the HOSP in n .4 l wummormmd mphwyl' 3% triphmyp composmons, it Will be noted, which are identified in l Table 11 below contain l-mono-chloro naphthalene as a 011% totrnchim'innteti diphonyl, 4% triphonyiimsphnto 33 as foamtng agent. The actual foaming test results the se sttttxtlsfisi.Titles :ffieiiitif'fi; a 30 f in T l w w TABLE II.IDENTIFICA'IION OF COMPOSITIONS (PERCENT WEIGHT) Number Components 'lriehiorinnted diphenyie. 'lutrnchlorlnoted tilphonyi lnntnuhlorlnutod diphenylo i)i-tert hutyi purucrosoi Calcium petroleum sultonntm. Octa docenyl sueeinic ncid llutyl polyncrylnto (ltLW.

TABLE [IL-AS'IM TEST D.043/54 Neutral Neutral Neutral Neutral Iron and copper Composinumber number number number Sludge or tlon No. before after after utter coils deposits test 500 a 1,000 n 2,000 n 0.05 0. 39 0. 7O Corrosion Siud e. 0. l0 0. 82 1. 05 (I o. 0. 05 0. 17 0. 39 Very little 5]. 0. 04 0.14 0. 29 No sludge. 0.05 0. 20 0. 52 Do. 0.06 1. 0'2 1. 77 Sludge. 0. O8 0. 95 l. 21 D0. 0.07 1.11 1. 92 D0. 0. 08 O. 99 1. 42 D0. 0. 09 0. 25 O. 51 Little sludge. 0.12 0.27 0. 43 N o sludge. 0. 05 0. l8 0. 32 Do. 0. 05 0. l4 0. 32 D0. 0. 06 0. l6 0. 35 D0. 0.06 0. 20 0. 41 Very little si. 0.12 0. 24 0. No sludge.

BEST AVAILABLE COPY TABLE IV.-FOAMINC1 'IEB'I ABIM DMZ/b8 '1 Foaming tendency, ml. loam alter Foam stability, m1. loam after 10 Comygositlon 6 minutes bubbllog atminutes rest at- 76' F 200 F. 76' F. 76' F. 200' F. 76' F.

610 630 630 480 10 200 400 280 670 Traced 10 200 160 100 200 0 0 90 70 0 0 0 1150 H3 171 0 0 0 After the 200' F. test.

it will be observed that above the 5% upper quantity limit of phosphoric acid the oil will deposit sludge despite the presence of anti-oxidant and will develop corrosive acidity despite the use of rust inhibitors.

As the tables show, the phosphate esters in the limited quantity are non-corrosive and do not deposit sludge. Moreover, they exhibit superior extreme pressure characteristics with respect to compositions of the art having higher quantities of phosphate esters. The triaryl phosphoric esters, for extreme pressure purposes, exhibit a striking maximum at around 3% as shown in the attached curves.

Certain modifications will occur to those skilled in the art and, accordingly, it is intended that the description: be regarded as illustrative and not limiting except as defined in the claims attached hereto.

What is claimed is:

1. A fire resistant, substantially non-sludging, substantially non-corrosive fluid consisting essentially of polychlorinated diphenyl containing about .5 to 5% by weight of a tri-monocarbocyclic aryl phosphoric acid ester and stabilizing amounts of an antioxidant and of a rust inhibitor.

2. The product as defined in claim 1 wherein the trimonocarbocyclic aryl radical is a member of the group consisting of phenyl, cresyl and xylenyl.

3. The composition as defined in claim 1 wherein the phosphate ester is tri-cresyl phosphate limited for extreme pressure properties to a quantity in the range of 2 to 4%.

References Cited UNITED STATES PATENTS Re. 23,229 5/1950 Griffin et a1 252-33.4 1,986,651 1/1935 Prutton 252-58 2,175,877 10/1939 Clark 252-499 2,245,649 6/1941 Caprio 252-499 2,707,176 4/1955 Gamrath et a1. 252-499 X 2,730,499 1/1956 Pokorny 252-499 X 2,794,782 6/1957 Cunningham 252-499 X 3,136,726 6/1964 Moreton 252-499 OTHER REFERENCES Egan, "Lubrication Engineering, Feb-Mar. 1947, pp. 24-26.

DANIEL E. WYMAN, Primary Examiner.

W. H. CANNON, Assistant Examiner. 

1. A FIRE RESISTANT, SUBSTANTIALLY NON-SLUDGING, SUBSTANTIALLY NON-CORROSIVE FLUID CONSISTING ESSENTIALLY OF POLYCHLORINATED DIPHENYL CONTAINING ABOUT .5 TO 5% BY WEIGHT OF A TRI-MONOCARBOCYCLIC ARYL PHOSPHORIC ACID ESTER AND STABILIZING AMOUNTS OF AN ANTIOXIDANT AND OF A RUST INHIBITOR.
 5. THE COMPOSITION OF CLAIM 1 CONTAINING AS A RUST INHIBITOR A SMALL QUANTITY OF A COMPOUND OF THE GROUP CONSISTING OF AN ALKALINE EARTH METAL SULFONATE, A HIGHER ALKYL SUCCINIC ACID AND MIXTURES THEREOF. 